Field of the Invention
This invention relates to a length-adjustable holding device with a resilient support for the lower steering arm of a three-point coupling device for an agricultural tractor, having a helical spring comprising a first connecting element, and an adjusting member adjustable received in the helical spring and comprising a second connecting member, with a pin being provided to secure the position of the adjusting member relative to the helical spring, which pin passes through the space between two spring coils and engages a bore of the adjusting member.
In order to change the effective length between the connecting elements of such prior art holding devices it is necessary to unfasten a connecting element to be able to rotate the adjusting member relative to the helical spring. This operation is complicated and requires a great deal of force.
There is a further disadvantage in that, due to the above way of operating, accurate adjustment is difficult because repeated unfastening of the connecting element would be necessary in order to find the accurate distance. Finally, the spring may disadvantageously be bent so that accurate guidance of the lower steering arm is not ensured.
Is it therefore the object of the invention to provide a holding device which ensures accurate guidance of the lower steering arm and whose length may be accurately set to the required dimension without having to unfasten the connecting element.